Buttonhole-sewing machine



H. c. SEAR LE. BUTTONHOLE SEWI NGMACHINE'. APPLICATION FILED 0CT.-28,19l5.

Patented Feb. 10, 1920',

' 2 SHEETS-SHE-ETI i.

' W Inventoni H. c; SEARLE. BUTTONljOLE SEWING MAQHINE. APPLICATION men qcT. zs; ms.

1,330,555. Patented Feb, 10, 1920.

2 SHEETS-SHEEI'Z- Inventor.-

Wiiiwssr y I UNITED STATES P ENT OFFICE.

HENRY o. SEARLE, 0E PEAK IsLAND, MAINE, ASsIGivqit, BY T'o UNITED SHOE MACHINERY CORPORATION, or PATERSON, NEW JERSEY, A CORPO- RATION OF NEW JERSEY.

Specification of Letters Patent,

Patented Feb; 10, 1920.

Application filed October 28, 1915. Serial No; 58,422.

sewing mechanism are relatively movable to form overedge stitches along the SlClGS and about the ends of a buttonhole.

In the class of machines to which the 1nvention is applicable, a stay cord is led through the throat plate so that it lies along the under edge of the buttonhole and is covered by the overedge stitches. In sewing a series of buttonholes the work is moved after the completion of a buttonhole to properly space the completed buttonhole with relation to the work clamp, and then the work is reclamped, preparatory to sewing the succeeding buttonhole. The stay cord usually extends from the completed and spaced buttonhole across the upper face of the throat plate to the needle hole, so that i it is pressed against the under surface of the work when the work is clamped, pre' paratory to sewing the succeeding buttonhole of the series. In such case the relative movement between the work clamp and sewing mechanism in bringing them from clamping and cutting to sewing relation causes the work to move over the upper surface of the throat plate and in so doing to draw the cord through the needle hole. The cord between the ends of successive buttonholes is therefore slack and more or less bowed, instead of leading in a straight line directly from one hole to another. It is the object of the present invention" to overcome this objection to the prior constructions, and to provide a throat plate and cooperating parts which will avoid the drawing of an objectionable amount of surplus cord through the throat plate, and the resulting objectionable slackness in the cord leading from one buttonhole to another. To this end the invention contemplates the provision in a machine inwhich there is part of its upper surface across which the cord or cord and under thread lead to the completed buttonhole recessed to avoid pressing the cord against the under surface of the work. WVith this construction the work will slide over the throat plate and cord. without drawing surplus cord through the throat plate, and without therefore producing an objectionable slackness in the cord between successive buttonholes. At the same time, the recessed part-of the throat plate affords an effective support for the work close to the path of the needle during the sewing. The surplus cord'may be further reduced, and the cord be drawn substantially taut between successive buttonholes by providing a spring takeup for the cord, and such a cord takeup forms a further feature of the invention. In case the side toward which the work is moved inspacing the buttonholes is preferably recessed at the end of the under jaw, and'the overhanging under surface of the upper jaw is also preferably recessed, so that the work and cord will not be pressed together between the end of the completed buttonhole and the throat plate.- The cord consequently leads freely from the end'of the spaced buttonhole through the throat plate, and is not pulled or bowed by the relative movement between the work clamp and throat plate. p

The invention will be readily understood from an inspection of the accompanying drawings and the following detailed description of the mechanism illustrated therein. 7,

In the drawings, Figure 1 is a partial plan view showing the throat plate and work clamping devices of a buttonhole sewing machine embodying the present improvements in their'pre'ferred forms; Fig. 2 is a vertiral sectional elevation showing the work clamping and sewing mechanisms; Fig. 3 is an enlarged detail plan view showing the throat plate detached; Fig". 4 is a sectional elevationof-the'throat plate; Fig, 5 is "a" transverse sectional elevation showing the work supporting plates and under thread handling and guiding devices; and Fig. 6 is a detail plan view showing the plate which is secured to the upper end of the turret,

and which supports the throat plate and cord takeup, the throat plate being removed.

In the drawings the invention is shown as embodied in a button-hole sewing machine having the general construction and mode of operation of the machine shown and described in Patent No. 1,063,880, June 3, 1913. In this machine the stitch forming mechanism comprises an upper needle 2, an under needle 4, and a looper 6. The upper needle is eccentrically mounted in a reciprocating needle bar 8 carried in a rotary head. The under needle and looper are mounted in a rotary turret 10. The turret and head are rotated through a single revolution during the sewing of a button-hole by mechanism which is fully illustrated and described in the patent above referred to. The work clamp comprises work supporting plates 12 pivoted at 14 upon a carrier 16 which is moved lengthwise of the buttonhole to move the work between the clamping and cutting and the sewing positions, and to feed the work during the sewing, and is moved laterally during the sewing about the eye and end of the button-hole by mechanism which is fully shown and described in the patent above referred to. The work supporting plates carry the work clamping jaws, the under jaws 18 being in the form of plates secured in recesses in the work supporting plates 12 with their upper face substantially flush with the upper surfaces of the work supporting plates. The upper jaws 20 are pivoted on the ends of clamping arms 22 which are pivoted to blocks 24 mounted on the work supporting plates, and are operated to open and close the clamps by suitable mechanism indicated in Fig. 2, and fully hown and described in the patent above referred to. The work is supported at the sewing point by a throat plate 26 which is secured to the turret, and is provided with a needle hole or slot 28 for the passage of the upper and under needles. The throat plate is provided with a cord guide 30 through which a stay cord is led to the needle hole and is presented in position to be covered by the stitches formed by the sewing mechanism.

In embodying the present improvements in a machine having the construction and mode of operation above described, the upper surface of the throat plate on that side of the needle hole toward which the work is moved in spacing the button-holes is provided with a recess or depression 32 through which the stay cord and under thread may be led to the end of a completed and spaced buttonhole when the work is clamped, prebring the work from cutting to sewing position. The forward movement of the work does not therefore draw slack or surplus cord through the throat plate, as would be the case if the upper surface of the throat plate were not recessed to give clearance between the throat plate and work along the path of the cord and under thread. The recess in the upper surface of the throat plate is not deep enough, however, to interfere with the proper support of the work about the needle hole during the sewing. In order that that part of the cord which leads from the side of the throat plate over the work supporting plate 12 to the end of the spaced buttonhole may be free to accommodate itself to the forward movement of the work clamp in bringing the work from cutting to sewing position, the upper surface of the work clamp is provided with a recess 34 extending from the side of the throat plate to the end of the under. work clamping jaw. This recess registers with and forms a continuation of the recess 32 in the throat plate, so that the cord and under thread lead freely from the end of the spaced buttonhole to the needle hole and cord guide in the throat plate. In case the upper clamping jaw 20 extends beyond the forward end of the under jaw 18, so that it will overlie the recess 34, the under surface of the overlying portion of the upper jaw is preferably cut away or recessed as indicated at 36 (Fig. 2) to avoid pressing the work down into the recess 34.

The machine is also preferably provided with a spring actuated cord takeup 38 which is mounted upon the turret, and through which the cord is led to the guide 30 in the throat plate. This takeup is in the form of a lever pivoted at 40 and held normally in position against a stop 42 by a spring 44. When the work is moved to space the completed buttonhole, the pull upon the cord draws the takeup forward against the tension of the spring 42. After the work has been clamped and the buttonhole cut, and as the work clamp moves forward to bring the work into sewing position, the takeup acts to keep the cord taut so that it will lead directly from the end of the completed buttonhole to the needle hole in the throat plate. This takeup may be used with advantage in constructions in which the throat plate is not provided with a recessed upper surface, as it will exert a backward pull upon the cord, and thus tend to prevent the drawing of surplus cord through the throat plate and to draw back any such cord.

l/Vhile it is preferred to employ the specific construction and arrangement of parts shown and described in embodying the invention in the machine shown and described in the patent above referred to, it will be understood that this construction and arrangement is not essential to the broader features of the invention, and may be varied or modified as found desirable or best suited to the construction and mode of operation of the machine in which it is to be embodied.

Having explained the nature and object of the invention, and specifically described one form of machine in which it may be embodied, what is claimed is 1. A buttonhole sewing machine, having, in

combination, a work clamp and stitch. forming mechanism relatively movable lengthwise of the buttonhole from clamping to sewing position, and a throat plate having in its upper surface a depression for the passage of the cord or thread leading to the end of a spaced buttonhole when the work is clamped preparatory to the sewing of the succeeding buttonhole.

2. A buttonhole sewing machine, having, in combination, stitch forming mechanism, a throat plate having a recessed upper surface on that side of the needle hole toward which the work is moved in spacing the buttonholes, and a work clamp provided with work supporting plates recessed on the corresponding side of the throat plate for the passage of the cord or threads leading from the end of the spaced buttonhole to the throat plate.

A buttonhole sewing machine, having, in combination, a work clamp and stitch forming mechanism comprising upper and under thread handling devices, a turret on which the thread handling devices are mounted, a throat plate on the turret, guides through which the stay cord is led to the throat plate, and a spring takeup for the cord.

A. A buttonhole sewing machine, having, in combination, a work clamp and stitch forming mechanism comprising upper and under thread handling devices, a turret on which the thread handling devices are mounted, a throat plate on the turret, guides through which the stay cord is led to the throat plate, a spring operated takeup on the turret through which the cord passes freely, and mechanism for relatively moving the work clamp and stitch forming mechanism from clamping to sewing relation.

5. A buttonhole sewing machine, having, in combination, a work clamp and rotary stitch forming mechanism relatively movable from clamping to sewing relation, a throat plate mounted to rotate with the stitch forming mechanism and having on its upper surface a depression for the passage of the cord or thread leading to the end of a spaced buttonhole when the work is clamped preparatory to sewing the succeeding buttonhole.

6. A buttonhole sewing machine, having, in combination, rotary stitch forming mechanism, a work clamp movable from clamping to sewing position, mechanism for" rotating the stitch forming mechanism and for moving the work clamp to sew about a buttonhole, and a throat plate mounted to rotate with the stitch forming mechanism and having on its upper surface a depression for the passage of the cord or thread leading to the end of a spaced buttonhole when the work is clamped preparatory to sewing the succeeding buttonhole.

HENRY C. SEARLE. 

